From d3d6712fa3f4e10858596e4ceef0b0fd9d8352db Mon Sep 17 00:00:00 2001
From: Harshit Bansal <harshitbansal2015@gmail.com>
Date: Sat, 1 Jul 2017 20:30:50 +0000
Subject: [PATCH] left-sidebar: Update the size of the scrollbar after
 narrowing to a stream.

---
 frontend_tests/node_tests/stream_list.js | 8 ++++++++
 static/js/stream_list.js                 | 2 ++
 2 files changed, 10 insertions(+)

diff --git a/frontend_tests/node_tests/stream_list.js b/frontend_tests/node_tests/stream_list.js
index 1168c485f4..deb09d9b59 100644
--- a/frontend_tests/node_tests/stream_list.js
+++ b/frontend_tests/node_tests/stream_list.js
@@ -242,6 +242,11 @@ function initialize_stream_data() {
     topic_list.rebuild = noop;
     stream_list.scroll_element_into_container = noop;
 
+    var scrollbar_updated = false;
+    $.stub_selector("#stream-filters-container", {
+        perfectScrollbar: function () { scrollbar_updated = true; },
+    });
+
     assert(!$('stub-devel').hasClass('active-filter'));
 
     stream_list.initialize();
@@ -260,7 +265,9 @@ function initialize_stream_data() {
     ]);
     activate_filter(filter);
     assert($('stub-devel').hasClass('active-filter'));
+    assert(scrollbar_updated);  // Make sure we are updating perfectScrollbar.
 
+    scrollbar_updated = false;
     filter = new Filter([
         {operator: 'stream', operand: 'cars'},
         {operator: 'topic', operand: 'sedans'},
@@ -268,6 +275,7 @@ function initialize_stream_data() {
     activate_filter(filter);
     assert(!$("ul.filters li").hasClass('active-filter'));
     assert(!$('stub-cars').hasClass('active-filter')); // false because of topic
+    assert(scrollbar_updated);  // Make sure we are updating perfectScrollbar.
 
     assert(!pm_expanded);
     filter = new Filter([
diff --git a/static/js/stream_list.js b/static/js/stream_list.js
index 83548998d3..549681a24b 100644
--- a/static/js/stream_list.js
+++ b/static/js/stream_list.js
@@ -461,6 +461,8 @@ exports.initialize = function () {
         if (stream_li) {
             exports.scroll_to_active_stream(stream_li);
         }
+        // Update scrollbar size.
+        $("#stream-filters-container").perfectScrollbar("update");
     });
 
     $(document).on('narrow_deactivated.zulip', function () {